In a typical multiple computer environment, a Local Area Network (“LAN”) or Wide Area Network (“WAN”) allows for each computer, or server, to be connected to several other computers such that the resources of each connected computer, or server, are available to each of the connected computers. In this networked environment, a dedicated keyboard, video monitor, mouse, audio output device, audio input device, and/or auxiliary peripheral devices may be employed for each computer or server.
To maintain proper operation of the LAN or WAN, the system administrator must maintain and monitor the individual computers including the servers. This maintenance frequently requires the system administrator to perform numerous tasks at the user console that is associated with and physically located at the computer or server. For example, to reboot a computer or to add or delete files, the system administrator is often required to operate the computer or server using its local, attached keyboard, mouse, video monitor, audio devices, and/or auxiliary peripheral devices, which may be located at a substantial distance from the system administrator's computer and from other computers or servers connected to the LAN or WAN. Consequently, to accomplish the task of system administration, the system administrator must often physically relocate to the user consoles of remote computers and servers.
One alternative to physical relocation of the system administrator is the installation of dedicated cables that connect each remote computer or server to the system administrator's computer in a manner that allows the system administrator to fully access and operate the remote computers or servers. However, such an alternative requires substantial wiring and wire harnessing, both of which may require tremendous cost that increases each time a new computer is added to the system. Additionally, as the distance between the system administrator's computer and the computer equipment increases, a decrease in the quality of the transmitted signal often results. Thus, dedicated cables between the system administrator's computer and remote computer equipment may not provide a feasible alternative.
In addition to the ease of managing a networked computer environment, space is also an important concern for many networked computer environments, especially large-scale operations such as data-centers, server-farms, web-hosting facilities, and call-centers. These computer environments typically require space to house a keyboard, video monitor, mouse, audio output device, audio input device and/or auxiliary peripheral devices for each computer in addition to all of the wiring required to connect and power each component to the respective computer. Furthermore, additional space is required to house the network interface components (e.g., a hub or other connection device) and wiring (i.e., the wiring that physically connects the computers together either directly or via network interface components). As more equipment is added to a computer network, it becomes more probable that the space required to house the equipment and associated cabling will exceed the space allotted for the computer network. Therefore, network architecture, equipment size, and available space are important issues when designing an effective computer network environment.
One method of reducing the amount of space required to house a computer network is to eliminate user interface devices (i.e., keyboard, video monitor, mouse, audio output device, audio input device, auxiliary peripheral devices, etc.) that are not essential for proper operation of the computer network. User interface devices, and associated wiring, may be eliminated if a system administrator is able to access the remote computers from the system administrator's computer, thereby eliminating the need for dedicated user interface equipment and its associated wiring.
Allowing a system administrator to operate remote computers or servers from the system administrator's computer eliminates the need for physical relocation of the system administrator to perform system maintenance or administration. Also, this capability decreases the amount of space required to house the computer network by eliminating unnecessary devices.
The following references, which are discussed below, were found to relate to the field of computer management systems: Asprey U.S. Pat. No. 5,257,390 (“Asprey '390 patent”), Asprey U.S. Pat. No. 5,268,676 (“Asprey '676 patent”), Asprey U.S. Pat. No. 5,353,409 (“Asprey '409 patent), Perholtz et al. U.S. Pat. No. 5,732,212 (“Perholtz”), Chen U.S. Pat. No. 5,978,389 (“Chen '389 patent”), Chen U.S. Pat. No. 6,119,148 (“Chen '148 patent”), Fujii et al. U.S. Pat. No. 6,138,191 (“Fujii”), Beasley U.S. Pat. No. 6,345,323 (“Beasley”), Pinkston, II et al. U.S. Pat. No. 6,378,009 (“Pinkston”), Thornton et al. U.S. Pat. No. 6,385,666 (“Thornton”), Ahern et al. U.S. Pat. No. 6,388,658 (“Ahern”), and Wilder et al. U.S. Pat. No. 6,557,170 (“Wilder”).
The Asprey '390 patent discloses an extended range communications link for coupling a computer to a keyboard, video monitor, and/or mouse that is located remotely from the computer. The end of the link that is coupled to the computer has a first signal conditioning circuit that conditions the keyboard, video monitor and mouse signals. Conditioning the video monitor signals includes reducing their amplitude in order to minimize the amount of “crosstalk” that is induced on the conductors adjacent to the video signal conductors during transmission of the video signals. This signal conditioning circuit is coupled to an extended range cable having a plurality of conductors that transmits the conditioned signals and power and logic ground potentials to a second signal conditioning circuit. This second signal conditioning circuit restores the video signals to their original amplitude.
The Asprey '676 patent discloses a communications link for use between a computer and a display unit, such as a video monitor, that allows these two components to be located up to three hundred (300) feet apart. An encoder located at the computer end of the communications link receives analog red, green and blue signals from the computer and inputs each signal to a discrete current amplifier that modulates the signal current. Impedance matching networks then match the impedance of the red, green and blue signals to the impedance of the cable and transmit the signals to discrete emitter-follower transistors located at the video monitor end of the cable. These transistors amplify the signal prior to inputting it to the video monitor. Concurrently, the horizontal synchronization signal is inputted to a cable conductor and its impedance is not matched to the impedance of the cable, thereby allowing the conductor to attenuate the horizontal synchronization signal and reduce noise radiation.
The Asprey '409 patent discloses an extended range communications link for transmitting transistor-transistor logic video signals from a local computer to a video monitor located up to a thousand (1,000) feet from the computer. The link includes a first signal conditioning circuit located at the computer end of the link for reducing the amplitude of the video signals received from the computer and biasing them to a selected potential, whereafter, they are applied to discrete conductors of the link. A second signal conditioning circuit receives and reconstructs the transmitted video signals prior to inputting them to the video monitor. According to the Asprey '409 patent, performance of this process reduces the appearance of high frequency video noise on the keyboard clock conductor of the transmission cable, thereby preventing keyboard errors. The Chen '389 patent discloses a video signal multiplexing device for use with a single video monitor that is capable of selecting one video signal from a plurality of computers for display on the video monitor. The Chen system includes three sets of switches for receiving the red, green, and blue components of the video signals from each computer. When a user selects the desired remote computer, an interface circuit generates a control signal that directs the three sets of switches to select the corresponding video signals from the plurality of computers. The selected signals are then transmitted to three sets of switch circuits and current amplifying circuits that provide input and output impedance matching, respectively. The selected video signal is then displayed on the video monitor.
Perholtz discloses a method and apparatus for coupling a local user workstation, including a keyboard, mouse, and/or video monitor, to a remote computer. Perholtz discloses a system wherein the remote computer is selected from a menu displayed on a standard size personal computer video monitor. Upon selection of a remote computer by the system user, the remote computer's video signals are transmitted to the local user workstation's video monitor. The system user may also control the remote computer utilizing the local user workstation's keyboard and monitor. The Perholtz system is also capable of bi-directionally transmitting mouse and keyboard signals between the local user workstation and the remote computer. The remote computer and the local user workstation may be connected either via the Public Switched Telephone System (“PSTN”) and modems or via direct cabling.
The Chen '148 patent discloses a video signal distributor that receives, processes and distributes video signals received from one or more computers to a plurality of video monitors. The video signal distributor includes three transistor-based voltage amplifying circuits to individually amplify the red, green and blue video signals received from each computer prior to transmitting these signals to a video monitor. The video signal distributor also includes a synchronization signal buffering device that receives horizontal and vertical synchronization signals from each computer and generates new synchronization signals based upon the quantity of video signals that are output to the video monitors.
Fujii discloses a system for selectively operating a plurality of computers that are connected to one common video monitor. The Fujii system includes a single interface device for entering data in any one of the plurality of connected computers. The system also includes a main control circuit, which is connected to the interface device, and a selection circuit for providing the entered data and receiving the video signals from the selected computer.
Similar to Perholtz, Beasley discloses a specific implementation of a computerized switching system for coupling a local keyboard, mouse and/or video monitor to one of a plurality of remote computers. In particular, a first signal conditioning unit includes an on-screen programming circuit that displays a list of connected remote computers on the local video monitor. To activate the menu, a user depresses, for example, the “print screen” key on the local keyboard. The user selects the desired computer from the list using the local keyboard and/or mouse.
According to Beasley, the on-screen programming circuit requires at least two sets of tri-state buffers, a single on-screen processor, an internal synchronization generator, a synchronization switch, a synchronization polarizer, and overlay control logic. The first set of tri-state buffers couples the red, green, and blue components of the video signals received from the remote computer to the video monitor. That is, when the first set of tri-state buffers are energized, the red, green, and blue video signals are passed from the remote computer to the local video monitor through the tri-state buffers. When the first set of tri-state buffers are not active, the video signals from the remote computer are blocked. Similarly, the second set of tri-state buffers couples the outputs of the single on-screen processor to the video monitor. When the second set of tri-state buffers is energized, the video output of the on-screen programming circuit is displayed on the local video monitor. When the second set of tri-state buffers is not active, the video output from the on-screen programming circuit is blocked. Alternatively, if both sets of tri-state buffers are energized, the remote computer video signals are combined with the video signals generated by the on-screen processor prior to display on the local video monitor.
The on-screen programming circuit disclosed in Beasley also produces its own horizontal and vertical synchronization signals. To dictate which characters are displayed on the video monitor, the CPU sends instructional data to the on-screen processor. This causes the on-screen processor to retrieve characters from an internal video RAM for display on the local video monitor.
The overlaid video image produced by the on-screen processor, namely a Motorola MC141543 on-screen processor, is limited to the size and quantity of colors and characters that are available with the single on-screen processor. In other words, the Beasley system is designed to produce an overlaid video that is sized for a standard size computer monitor (i.e., not a wall-size or multiple monitor type video display) and is limited to the quantity of colors and characters provided by the single on-screen processor.
During operation of the Beasley system, a remote computer is chosen from the overlaid video display. Thereafter, the first signal conditioning unit receives keyboard and mouse signals from the local keyboard and mouse and generates a data packet for transmission to a central cross point switch. The cross point switch routes the data packet to the second signal conditioning unit, which is coupled to the selected remote computer. The second signal conditioning unit then routes the keyboard and mouse command signals to the keyboard and mouse connectors of the remote computer. Similarly, video signals produced by the remote computer are routed from the remote computer through the second signal conditioning unit, the cross point switch, and the first signal conditioning unit to the local video monitor. The horizontal and vertical synchronization video signals received from the remote computer are encoded on one of the red, green or blue video signals. This encoding reduces the quantity of cables required to transmit the video signals from the remote computer to the local video monitor.
Pinkston discloses a keyboard, video, mouse (“KVM”) switching system capable of coupling to a standard network (e.g., a Local Area Network) operating with a standard network protocol (e.g., Ethernet, TCP/IP, etc.). The system of Pinkston couples a central switch to a plurality of computers and at least one user station having a keyboard, video monitor, and mouse. The central switch includes a network interface card (“NIC”) for connecting the central switch to a network, which may include a number of additional computers or remote terminals. Utilizing the Pinkston system, a user located at a remote terminal attached to the network may control any of the computers coupled to the central switch.
Thornton discloses a computer system having remotely located I/O devices. The system of Thornton includes a computer, a first interface device, and a remotely located second interface device. The first interface device is coupled to the computer and the second interface device is coupled to a video monitor and as many as three I/O devices (e.g., keyboard, mouse, printer, joystick, trackball, etc.) such that a human interface is created. The first and second interface devices are coupled to each other via a four wire cable. The first interface device receives video signals from the connected computer and encodes the horizontal and vertical synchronization signals of the received video signals onto at least one of the red, green, and blue components of the video signal. The first interface device also encodes the I/O signals received from the connected computer into a data packet for transmission over the fourth wire in the four wire cable. Thereafter, the encoded, red, green, and blue components of the video signals and the data packet are transmitted to the second interface device located at the human interface. The second interface device decodes the encoded red, green, and blue components of the video signal, separates the encoded horizontal and vertical synchronization signals, and decodes the I/O signal data packet. The video signal and the synchronization signals are then output to the video monitor attached to the second interface and the decoded I/O signals are routed to the proper I/O device, also attached to the second interface. The second interface device may optionally include circuitry to encode I/O signals received from the I/O devices attached to the second interface for transmission to the first interface device.
Ahern discloses a switching system for interconnecting a plurality of computer user terminals with a plurality of computers via a computer network, thereby allowing a user to access any computer from any computer user terminal. Each computer is interfaced to the switching system via a computer interface, which conditions the bi-directional keyboard and mouse signals and the uni-directional video signals for transmission over a single CAT 5 cable to a central switch. The computer interface also encodes the bi-directional keyboard and mouse signals with the horizontal and vertical synchronization signals into a data packet for transmission over one of the twisted pair in the CAT 5 cable. The uni-directional red, green, and blue components of the video signals are transmitted as analog signals over the remaining three twisted pair in the CAT 5 cable. The central switch contains a series of digital cross point switches for routing the encoded data packet to the intended user interface module, as well as a series of analog cross point switches for routing the red, green, and blue components of the video signals to the same user interface module. Each user interface module is attached to the central switch via a single CAT 5 cable. The user interface module decodes the bi-directional keyboard and mouse signals and outputs them to the keyboard and mouse attached to the user interface. Similarly, the user interface module decodes the horizontal and vertical synchronization signals and outputs the resulting signals as well as the analog red, green, and blue components of the video signal to the video monitor attached to the user interface.
Wilder discloses a keyboard, video, mouse and power switching (“KVMP”) apparatus for connecting a plurality of computers to one or more user stations having an attached keyboard, video monitor, and mouse. On-screen display (“OSD”) circuitry embedded within the KVMP switching apparatus allows a user located at a user station to select and operate any one of the computers utilizing the keyboard, video monitor, and mouse attached to the user station. Secondary switching circuitry located within the KVMP switching apparatus allows a user located at a user station to additionally control the electrical power supply supplying each computer.
In view of the foregoing, a need clearly exists for a multimedia-capable remote computer management system that minimizes expensive, space-consuming, external computer hardware, while providing full access and control to multiple remote computers. Such a system should also allow one or more user workstations to access any one of a plurality of remote computers and its associated audio and auxiliary peripheral devices. Furthermore, such a system should greatly enhance the ability of information technology personnel to manage multiple computers or servers in both small-scale computer centers and large-scale operations such as data-centers, server-farms, web-hosting facilities, and call-centers.